This invention relates to spark gap switches for electrical circuits. Switching energy from capacitative or inductive circuits into a load circuit entails problems resulting from the sudden release of energy at the switch. Metallic contact switches tend to burn, to be eroded, or to weld together due to the high temperature produced by the high current.
One solution is to never allow the two conductors to come close to one another, and to let a spark conduct the current. Spark gap switches are commonly used to dump stored energy of a Joule or larger at voltages of tens of kilovolts. Gas, either at atmospheric or super-atmospheric pressure, is used as a dielectric. By one of several special techniques, the spark gap switch can be initiated with jitter and turn on time of as low as ten nanoseconds. Several prior art spark gap devices are shown in U.S. Pat. Nos. 2,817,036; 2,909,695; 3,030,547; and 3,543,075.
For many purposes a nanosecond switch operation is desired, which requires very low inductance which in turn requires small size. As the gap must hold off the voltage, the small size dictates high dielectric strength. This may be obtained by raising the gap gas pressure and by using a liquid as the dielectric. In the present invention, a dielectric liquid or saturated vapor is preferred.
It is an object of the invention to provide a new and improved spark gap switch which switch can be small and compact and have turn on times in the order of a few nanoseconds. A further object is to provide such a switch which can utilize a continuous flow of the dielectric through the gap between the electrodes. An additional object of the invention is to provide such a switch wherein a central and an annular electrode are positioned in the dielectric flow path. A specific object is to provide such a switch which can utilize coaxial and parallel plate transmission lines for electrical connections to the electrodes.
Other objects, advantages, features and results will more fully appear in the course of the following description.